HEAT AND MASS TRANSFER IN DISPERSE AND POROUS MEDIA
SIMULATION OF THE TRANSFER
OF WATER WITH A FINE-DISPERSE
GAS PHASE IN POROUS MEDIA
A. Yu. Dem’yanov,a O. Yu. Dinariev,b
and E. N. Ivanovb
The problem on the transfer of a three-phase water–gas–oil mixture in a porous medium was solved for the
case where the water contains a fine-disperse gas phase in the form of microsized or nanosized bubbles. It
was suggested that the transfer of bubbles is mainly due to the flow of the disperse phase (water). In this
case, the large aggregates of the gas phase in the porous space, in the water, and in the oil are transferred
in accordance with the modified Darcy law for multiphase mixtures. A mathematical model of movement of
the indicated mixture has been constructed for the case where the main phases (water, gas, and oil) adhere
to the filtration equations and the fine-disperse gas phase is defined by a kinetic equation like the Boltzmann
equation. Some one-dimensional numerical solutions of the indicated problem were analyzed.
Keywords: fine-disperse gas, filtration in a porous medium, kinetic equation.
ON THE PROBLEM OF EVALUATION OF HYDRAULIC
DRAG OF POROUS STRUCTURES
F. P. Ivanov
A comparative analysis of the coefficients of hydraulic drag in coolant flow in sintered porous structures is
performed. Equations for appraisal calculations are recommended.
Keywords: heat transfer, sintered porous structures, hydraulic drag, coefficients of viscosity and inertia, specific
pressure drop, filtration.
ACCOUNT OF THE COMPRESSIBILITY OF THE SOLID
PHASE IN GAS FLOW THROUGH POROUS MEDIA
N. S. Belyakov,a N. A. Lutsenko,a,b
S. S. Minaev,c and Yu. S. Teplitskiid
A study is made of the problem of taking account of the compressibility of the solid phase at high pressures
in problems of gas flow through porous media for linear filtration and nonlinear filtration alike. For this purpose,
the problems of one-dimensional steady-state gas flow through a porous medium have been solved and
analyzed for a compressible and an incompressible solid porous skeleton at a known pressure difference. It
has been shown that in taking account of the compressibility, the maximum relative deviations of the sought
quantities from the value calculated disregarding it depend linearly, as a rule, on the compressibility factor
and the pressure of the gas at entry into the porous medium. However in the case of nonlinear filtration, in
media with a high permeability, taking account of the compressibility is also influenced by the filtration coefficient
and by the inertial coefficient of drag of the porous medium. Nonlinear dependences of the maximum
relative changes in the sought quantities on the problem’s parameters arise.
Keywords: filtration of a gas, porous medium, compressibility.
CALCULATION OF THE EFFICIENCY
OF CIRCULAR POROUS CHANNELS
BY THE MODIFIED GUHMAN METHOD
A. P. Lukisha
Results of calculation of the efficiency of circular porous channels in the transient region 2300 ≤ Resm ≤
10,000 of movement of an incompressible coolant (water) in smooth-wall channels compared with the porous
channels at the first-kind boundary conditions are presented. The efficiencies of circular porous channels and
smooth-wall ones were compared using the modified Guhman method, in accordance with which the efficiency
of a short porous channel, in which a coolant is rapidly heated, is determined by comparison of this channel
with a long smooth-wall channel. As a criterion for selection of the length of a circular porous channel, the
attainment of the value 0.8 by the average dimensionless temperature of the liquid at the output of this channel
was used. The influence of different design and regime parameters of the channels being compared on
their efficiencies was investigated and the parameters, at which the gain in heat transfer superpasses the loss
in hydraulics, were determined.
Keywords: efficiency, porous channels, the transient region between the laminar and turbulent regimes of movement
of an incompressible coolant, the first-kind boundary conditions.
CENTRIFUGAL DEWATERING AND DRYING
OF HIGH-MOISTURE WOOD
V. P. Kozhin
The results of investigation of centrifugal dewatering and rotation-convection drying of water-saturated wood
which stayed under water for a few decades are presented.
Keywords: centrifuge, dewatering, drying, wood, submerged.
VIBRORHEOLOGICAL MODEL OF THE
VIBROFLUIDIZED BED OF DRY SUBSTANCES
S. A. Rusanov, K. V. Lunyaka,
and G. V. Nikitenko
Problems connected with theoretical aspects of the process of vibrofluidization of dry substances have been
considered. We present some theoretical results that make it possible to analyze more thoroughly the behavior
of dispersive materials in the process of vibrofluidization with account for the gas flow through the bed and
automatize the above calculations.
Keywords: vibrofluidized bed, two-phase flow, flow curves, numerical calculations, vibrorheology.
INFLUENCE OF VIBROWAVE ACTION
ON THE CHARACTER OF PRESSURE
DISTRIBUTION IN A BED
E. M. Abbasov and N. A. Agaeva UDC 532.546
The influence of different forms of elastic waves generated on the bottom hole on the character of pressure
distribution in the bed has been studied on the basis of theoretical investigations. The depth and dynamics of
propagation of the elastic waves in the bed as functions of the form of generated elastic waves have been determined.
Keywords: filtration, pressure, bed, vibrowave action, differential equation, Bessel function, period, fluid.
CARRY-OVER OF PARTICLES IN A CYCLONE CHAMBER
E. A. Pitsukha,a Yu. S. Teplitskii,b
and V. A. Borodulyab
The carry-over of clay and crushed-rice particles in a cyclone chamber of diameter 0.393 m was experimentally
investigated for different heights of introduction of a polyfractional disperse material. The maximum diameter
of the carried particles was calculated in relation to the velocity of air at the output of the nozzles
and the diameter of the outlet (exhaust port) of the chamber. The influence of the bottom flow on the carryover
of particles in the indicated chamber was determined.
Keywords: cyclone chamber, carry-over of particles, maximum diameter of the carried particles, bottom blow,
COMPARISON OF CALCULATIONS
BY THE TWO-FIELD VIBROFLUIDIZED-BED
MODEL WITH EXPERIMENTAL DATA
N. S. Orlova
A two-fluid vibrofluidized-bed model based on the Euler approach and Darcy law is investigated. Satisfactory
agreement of numerical calculations with experimental data on the change in the position of the lower boundary
of a thick layer of finely divided particles and of pressure in its lower part as functions of the vibration
phase of the shelf has been obtained.
Keywords: two-fluid model, vibrofluidized bed, Euler approach, Darcy law, gas pressure, numerical calculations.
THERMOMECHANICS OF THE GRANULAR
BED T-JOINT WATER HEATER
Yu. S. Teplitskii and D. G. Belonovich
On the basis of the heat transfer model taking into account the radiative transport the temperature distribution
and the resistance of the water heater with a granular packing having two independent air inlets have
been investigated. The generalized dependence for calculating the resistance of the granular bed has been
Keywords: ring bed, air heater, heat transfer model, radiative heat transfer.
NUMERICAL MODELING OF A NONMONOTONIC
SEPARATION HYDROCYCLONE CURVE
L. L. Min’kova and J. H. Dueckb
In the context of the mechanics of interpenetrating continua, numerical modeling of separation of a polydisperse
suspension in a hydrocyclone is carried out. The so-called "mixture model" valid for a low volume fraction
of particles and low Stokes numbers is used for description of the suspension and particle motion. It is
shown that account taken of the interaction between large and small particles can explain the nonmonotonic
behavior of the separation curve.
Keywords: numerical modeling, hydrocyclone, separation function, "fish-hook" effect, accelerated settling of
small particles, polydisperse suspension.
NONSTATIONARY MASS TRANSFER IN A DRYING
CHAMBER–ADSORBER SYSTEM UNDER CONDITIONS
OF NONEQUILIBRIUM ADSORPTION OF STEAM
P. A. Vakul’chik,a V. K. Kulikovskii,b
N. V. Pavlyukevich,a and Yu. I. Aristovc
Simulation of filtration and nonequilibrium adsorption of steam in an adsorber and a comparison of calculated
and experimental data were carried out.
Keywords: adsorption, filtration, steam, isotherm, relaxation time.
HEAT AND MASS TRANSFER IN COMBUSTION PROCESSES
CHANGE IN THE REGIMES OF FLOW AND COMBUSTION
IN A CHANNEL UNDER EXTERNAL ENERGY ACTION
V. A. Zabaikin, I. E. Naumov,
and P. K. Tret’yakov
The influence of the energy impulse-periodic action on the structure of the hydrogen-air mixture flow in a
channel for going from the regime of diffusion combustion of the mixture to pseudojump-like combustion has
been investigated. Experiments were carried out in a rectangular channel with sections of variable and constant
cross-section. The energy input was controlled with the aid of a heat-gas-dynamic pulse generator in
which a hydrogen-air mixture was burned. The intensity and regimes of combustion were determined by the
flame radiation in the ultraviolet spectral region and static pressure measurements. In the course of experiments,
the possibility of going from diffusion to pseudojump-like combustion under periodic energy and kinetic
actions on the mixture flow has been confirmed.
Keywords: pseudojump-like regime, combustion, impulse-periodic and kinetic action, rectangular channel, heatgas-
dynamic pulse generator, optical recording.
PYROLYSIS OF BROWN COALS
OF THE LELCHITSY DEPOSIT
I. I. Lishtvan, P. L. Falyushin,*
V. M. Kraiko, and V. M. Dudarchik
Results of experimental studies on pyrolysis of brown coals of the Lelchitsy deposit, which were conducted on
Laboratory setups in stationary and moving layers for producing high-caloric energy carriers, are presented.
The yield of the pyrolysis products is determined; the chemical composition of solid, liquid, and gaseous
products of thermochemical treatment is considered.
Keywords: brown coal, pyrolysis, thermal decomposition, energy carriers, combustion heat.
CONCERNING THE PROBLEM OF DYNAMIC DAMPING
OF THE VIBRATION COMBUSTION SELF-OSCILLATIONS
IN A LIQUID-PROPELLANT ROCKET ENGINE
B. I. Basok,a V. V. Gotsulenko,a
and V. N. Gotsulenkob
The reason for the decrease in the amplitude of longitudinal vibration combustion self-oscillations in the combustion
chamber of a liquid-propellant rocket engine by means of antipulse partitions has been justified. A
mathematical model of the development of combustion instability in such a chamber on attachment of a Helmholtz
resonator to it has been obtained. The character of the damping of vibration combustion self-oscillations
excited by the action of the Crocco mechanisms and negative thermal resistance, when varying the acoustic
parameters of the resonator and of the pressure head characteristics of combustion chamber is established.
Keywords: vibration combustion self-oscillations, Helmholtz resonator, damping of self-oscillation, wave resistance,
HYDROGASDYNAMICS IN TECHNOLOGICAL PROCESSES
MODULATION OF SOUND OSCILLATIONS
IN A FIELD WITH DISSIMILAR SOURCES
OF HYDRODYNAMIC PERTURBATIONS
R. K. Karavosov and A. G. Prozorov UDC 621.51:532; 533.6.071.4
Sound oscillations in the near field of the open working sections of two different wind tunnels are investigated.
It was established by measuring the spectra of pressure fluctuations that the amplitude modulation of
oscillations and the formation of their packets are typical of the cases considered. A more complete picture
of the transient regime of flow in the mixing layer of a free jet in the working section of a wind tunnel is
obtained. The well-known results of natural observations at the Sayano-Shushenskaya hydroelectric station are
Keywords: auto-oscillations, acoustic radiation, wind tunnel, Tollmien–Schlichting waves, hydroacoustic resonance,
infrasound, modulation, self-excitation, noise meter.
SIMULATION OF A TURBULENT SUPERSONIC
UNDEREXPANDED JET FLOWING INTO
A SUBMERGED SPACE WITH THE HELP
OF A SHEAR STRESS TRANSFER MODEL
S. A. Isaev,a Yu. M. Lipnitskii,b P. A. Baranov,c
A. V. Panasenko,b and A. E. Usachovd
We have calculated the flow of an axisymmetric turbulent supersonic underexpanded jet into a submerged
space with the help of the VP2/3 package as part of the generalized pressure correction procedure. The shear
stress transfer model modified with account for the curvature of streamlines has been verified on the basis of
comparison with V. I. Zapryagaev’s data obtained at the S. A. Khristianovich Institute of Theoretical and Applied
Mechanics, Siberian Branch of the Russian Academy of Sciences. The influence of the generated vortex
viscosity on the shock-wave structure of the jet, the field of flow parameters, and the turbulence characteristics
has been analyzed.
Keywords: shock-wave structure, supersonic underexpanded jet, turbulence, calculation, SST model, tube tests,
pressure correction procedure, SLAU, multiblock computational technologies, VP2/3 package.
CONTROL OF TRANSONIC FLOW PAST AIRCRAFT
ELEMENTS USING DIFFERENT EXTERNAL ENERGY
S. M. Aul’chenko, V. P. Zamuraev,
and A. P. Kalinina
A study has been made of the influence of pulsed-periodic energy supply on transonic regimes of flow past a
body of revolution for different source models. The possibility of restructuring significantly the flow has been
shown, which can serve as a basis for efficient control of flow past the entire aircraft and its elements alike.
Keywords: transonic flow, body of revolution, pulsed energy supply, Euler equations.
REDUCING THE WAVE DRAG OF WING AIRFOILS
IN TRANSONIC FLOW REGIMES BY THE FORCE ACTION
OF AIRFOIL SURFACE ELEMENTS ON THE FLOW
S. M. Aul’chenko and V. P. Zamuraev UDC 533.6.011
Mathematical modeling of the influence of forced oscillations of surface elements of a wing airfoil on the
shock-wave structure of transonic flow past it has been carried out. The qualitative and quantitative influence
of the oscillation parameters on the wave drag of the airfoil has been investigated.
Keywords: transonic flow past a wing airfoil, forced oscillations, wave drag.
SIMULATION OF THE HEAT EXCHANGE BETWEEN
THE SUPERSONIC FLOW AND THE STATIONARY
BODY IN A GAS CENTRIFUGE
K. V. Zvonarev, V. D. Seleznev,
V. I. Tokmantsev, and Yu. V. Abramov
We have made comparative calculations of the heat exchange in the subpersonic flow of gaseous UF6 around
the stationary cylindrical body inside the rotating rotor of the gas centrifuge. It has been revealed that the
integral heat flux from the gas to the body calculated with the use of the ANSYS-CFX program complex from
the viewpoint of the continuum model is much smaller than the heat flow calculated by the Monte Carlo
method of direct statistical simulation. Estimates show that under the conditions being considered the boundary
layer on the surface of the body has no time to be formed and has a thickness of the order of the mean
free path of the gas molecules and, therefore, the use of the methods of continuum mechanics in this region
is incorrect. On the contrary, the method of direct statistical simulation permits taking into account the interaction
of gas molecules directly with the surface of the streamline body and obtaining more correct results.
Keywords: gas centrifuge, ANSYS-CFX, Monte Carlo method, heat exchange, supersonic flow.
INVESTIGATION OF THE ACTION OF A TRANSVERSE
FLOW ON INJECTED NORMALLY VERTICAL ELEVATED
K. G. Dobrosel’skii UDC 533.6.071.4
The action of a turbulent air flow on injected normally vertical elevated low-head axisymmetric jets has been
investigated experimentally. Empirical formulas have been obtained for the geometry of the axes of isothermal
and slightly nonisothermal jets and for dimensionless velocities and temperatures in their cross sections. It
has been shown that the above jets are of a higher ejection ability in the transverse flow than submerged jets
Keywords: jet, flow, jet axis, velocity and temperature profiles.
BIFURCATION OF VISCOELASTIC FLUID COUNTERFLOWS
I. A. Makarov UDC 532.5.013.4:532.135
One of the phenomena of structural instability observed earlier in viscoelastic fluid flows in cross-channels,
namely, the asymmetry of flows in the region of the central singular point is considered. It is shown analytically,
by demonstrating symmetric and asymmetric asymptotic solutions in the vicinity of this singular point,
that the latter exhibits bifurcation. The fields of velocities and distributions of stresses and pressure provided
by asymptotic solutions are compared with their analogs observed experimentally and in numerical simulation.
Close association of the existence of asymmetric flows with the viscoelastic nature of fluid is shown.
Keywords: viscoelastic fluid, flow with a singular point, asymmetry, bifurcation.
ON AN INFLOW OF A MULTICOMPONENT
MIXTURE IN A VACUUM
V. S. Surov UDC 532.529.5
A self-similar problem on an inflow of a multicomponent mixture in a vacuum was solved for a multivelocity
model of a heterogeneous medium.
Keywords: multivelocity multicomponent medium, hyperbolic system of partial differential equations, self-similar
ANALYSIS OF THE TEMPERATURE DISTRIBUTION
IN THE EXPLOSION OF A METHANE/AIR MIXTURE
IN A TUNNEL
Qi Zhang and Lei Pang UDC 532.5
The aim of this work is to investigate temperature distribution in methane/air mixture explosion near a wall
of a tunnel by numerical simulation. The results obtained on the basis of the hypothesis of an adiabatic wall
are compared with those for a nonadiabatic wall. It is shown that the temperature near the wall in explosion
of methane/air mixtures in tunnels changes abruptly. The hypothesis of an adiabatic wall leads to a great
error in the calculated temperature near the wall. If heat conduction in the wall is ignored, the temperatures
at various locations of a section are almost equal, whereas the measured temperatures on the vessel wall are
always lower than those calculated on the basis of the hypothesis mentioned. However, when it is necessary
to find the temperatures in the field outside the range near the wall, heat conduction in it can be ignored.
Keywords: methane/air mixtures, temperature of explosion, numerical simulation, adiabatic wall.
ANALYSIS OF FREE OSCILLATIONS
OF THIN-WALLED CYLINDRICAL SHELLS
CONTAINING A COMPRESSIBLE LIQUID
A. I. Seifullaev, G. A. Mamedova,
M. A. Rustamova, and A. O. Yuzbasheva
Free oscillations of a thin-walled cylindrical cell containing a compressible liquid were investigated. At some
values of the parameters of the system, its eigenfrequencies were determined, and the influence of the geometric
and physical parameters of the cylindrical shell–liquid system on the free oscillation of cylinder was investigated.
Keywords: stress, oscillations, wave, frequency, density, shell.
STRUCTURE OF CARBON FILMS DEPOSITED
FROM A GAS DISCHARGE AT ATMOSPHERIC
S. V. Shushkov,a I. S. Krylov,a S. V. Gusakova,b
M. A. Silenkov,c and S. A. Zhdanoka
Carbon films were formed on anode (Ni, Cu) substrates from a low-current (10–100 mA) discharge in a
He/CH4 mixture at atmospheric pressure. In the case of deposition on substrates without heating, amorphous
films with a submicron fractal structure of the surface are formed. Films grown on a heated (1000oC) substrate
have a sandwich graphitized structure.
Keywords: gas discharge, plasma deposition, carbon films, graphene structures.
NANOFLUID JET IMPINGEMENT HEAT TRANSFER
CHARACTERISTICS IN THE RECTANGULAR
MINI-FIN HEAT SINK
Paisarn Naphon and Lursukd Nakharintr
The nanofluid jet impingement heat transfer characteristics in a rectangular mini-fin heat sink are studied.
The heat sink is fabricated from aluminum by a wire electrical discharge machine. The nanofluid is a mixture
of deionized water and nanoscale TiO2 particles with a volume nanoparticle concentration of 0.2%. The results
obtained for nanofluid jet impingement cooling in the rectangular mini-fin heat sink are compared with
those found in the water jet impingement cooling. The effects of the inlet temperature of the nanofluid, its
Reynolds number, and the heat flux on the heat transfer characteristics of the rectangular mini-fin heat sink
are considered. It is found that the average heat transfer rates for the nanofluid as coolant are higher than
those for deionized water.
Keywords: jet impingement, nanofluids, rectangular mini-fin heat sink.
HEAT CONDUCTION AND HEAT TRANSFER IN TECHNOLOGICAL PROCESSES
ANALYTICAL SOLUTION OF THE STEFAN
PROBLEM WITH ACCOUNT FOR THE ABLATION
AND THE TEMPERATURE-DISTURBANCE FRONT
V. A. Kudinov, A. V. Eremin, and I. V. Kudinov
An approximate analytical solution of the problem on the heat conduction of an infinite plate has been obtained
on the basis of the determination of the temperature-disturbance front and the introduction of additional
boundary conditions with account for the movement of the melting front in the case where the melted
substance is completely removed (Stefan problem with ablation). A method for construction of additional
boundary conditions, which allows one to obtain solutions of the indicated problem for engineering applications
in the form of simple algebraic polynomials free of special functions, is proposed. The accuracy of these
solutions is determined by the number of approximations, which is not limited in the case where additional
boundary conditions are used.
Keywords: integral methods, Stefan problem, temperature-disturbance front, melting front, heat of phase transition,
ablation, additional boundary conditions.
NONSTATIONARY END HEATING
OF A MULTILAYER SEMIINFINITE PLATE
I. N. Turchin
The solution of a two-dimensional initial boundary-value heat-conduction problem for a multilayer semiinfinite
band (plate) has been constructed with integral Laguerre and Fourier transformations. The results of a numerical
analysis of the temperature field in a three-layered plate as a function of the relative geometric and
thermophysical properties of the plate’s components have been given. The possibility of applying the method
proposed to analysis of temperature fields in bodies with nanocoatings has been elucidated.
Keywords: nonstationary heat conduction, multilayer plate, integral Fourier transformation, Laguerre polynomials.
COMPENSATION EFFECT OF VISCOSITY
IN MULTICOMPONENT HIGH-MOLECULAR-WEIGHT
M. Yu. Dolomatov and S. V. Dezortsev
The presence of the compensation effect of dynamic viscosity for multicomponent systems produced in different
ways (physical mixing, chemical reactions) is established. The growth in the entropy term ΔS as part of the
preexponent of the Frenkel equation is accompanied by the change in the activation energy Ea of viscous
flow. An analysis of the available results shows that this phenomenon is universal in character for hydrocarbon
Keywords: compensation effect of dynamic viscosity, high-boiling oil fractions, activation energy of viscous flow,
entropy of activation of viscous flow.
DETERMINATION OF THE SURFACE ENERGY
OF A SOLID BY ITS CRITICAL SURFACE TENSION
V. M. Gasanov
The energy of solid surfaces of fluoroplastic, polyethylene, graphite, glass, and zinc at the solid–gas and
solid–liquid interfaces was determined by the critical surface energy of these substances in the case of their
complete wetting, where the equilibrium boundary wetting angle is equal to unity or zero. Equations for determining
the equilibrium boundary angle of wetting of the surface of a solid by the surface tensions at the
solid–liquid–gas interfaces without account for the gravitation and hysteresis effects are proposed.
Keywords: equilibrium boundary wetting angle, surface energy of a solid, interface energy.